In WebAssembly, a function starts with a number of local variable
declarations, sometimes called a function header. These declarations are
*not* instructions, but they are considered to be part of the function,
meaning we can't just pretend like the function starts on the first
instruction. Instead, we treat them like a prologue, albeit one that you
cannot disassemble or set a breakpoint on.
With this PR, we now correctly disassemble the function, matching the
output of `objdump` and breakpoints resolve to the first instruction.
Fixes#189960
58a5ce4997